Conveying device



June 20, 1961 w, RUEGER 2,989,029

CONVEYING DEVICE Filed May 28, 1959 11 10 }-2 FIGMI IN VEN TOR. WILLIAM J. RUEGER AGENT Sratcs Paten Ofl ce 2,989,029 Patented June 20, 1961 r V r 2,989,029 CONVEYING DEVICE William]. Rueger, Yorktown Heights, N.Y., assignor to International Business Machines Corporation, New York, N.Y., a corporation of New York Y Y Filed May 28, 1959, Ser. No. 816,526

5 Claims. (Cl. 118-640) This invention relates to conveying devices and more particularly to magnetic conveying devices for transporting comminuted magnetic material.

It has been found that the instant invention has been especially useful in magnetic printing machines, such as that described in the Rueger US. Patent 2,820,9'5 6, wherein a latent magnetic image in character configuration is formed on the magnetizable surface of a drum by ma-g- 'netic recording heads, the latent image thus formed then being developed by the deposition thereon of finely divided particles of magnetic ink, which adhere only to the magnetized character areas so as to permit the subsequent transfer from the drum to a paper web where the ink is made permanent by a fixing process such as by the application of heat and pressure, or by chemical reaction. In such an application it is a requisite to good printing quality that the quantity of magnetic ink applied to the drum image be accurately metered, and more important that the ink be applied to the drum in a uniform dispersion so as to achieve a uniform density of the characters throughout the printing. It is to the end of delivering a controlled quantity of magnetic ink in a uniform dispersion to a printing machine of this type that the instant invention is particularly adapted.

It is therefore an object of this invention to provide an apparatus for conveying and delivering toa utilization device a controlled quantity of comminuted magnetic material in a uniform dispersion.

A further object is to provide an apparatus in accordance with the foregoing object wherein transfer means are provided for separating the comminuted material in its uniformly dispersed form from the conveyer at a predetermined delivery point in the path of the conveyance.

Yet another object of the instant invention is to provide a magnetic conveying and delivering apparatus for comminuted magnetic material wherein the apparatus is so configured that during the course of said transport the material is dispersed and aligned thereover in an even distribution, there being means at the delivery point for selectively controlling the transfer of the material from the conveying apparatus to the utilization device for the material so conveyed.

An even further object is to provide a magnetic conveying and delivery apparatus for magnetic comminuted material having provision for controlling the quantity of material to be delivered to the utilization device in a uniform dispersion.

A final and specific object of this invention is to provide a magnetic conveying and delivering apparatus for conveying comminuted magnetic material from a bulk source and delivering it in a controlled quantity and in a uniform dispersion to a utilization device wherein the apparatus comprises a hollow drum comprised of a plurality of parallel, spaced magnetic segments embedded in a non-magnetic material so as to form a smooth exterior cylindrical surface, electromagnetic means internal of the cylinder for magnetizing adjacent segments with opposite polarity for a predetermined arc of travel of the segments, a resilient non-magnetic sleeve surrounding the cylinder, and fluid discharge means for flexing the sleeve away from the drum to deliver the magnetic material to the utilization device.

The foregoing and other objects, features andadvan- 2 tages of the invention will be apparent from the following more particular description of apreferred embodiment of the invention, as illustrated in the accompanying drawing. In the drawing:

FIGURE 1 is a transverse section through the applicator.

FIGURE 2 is an axial section of the device.

FIGURE 3 is an isometric view with certain portions of the device removed.

In FIGURE 1 the orientation of the conveying apparatus of the instant invention is shown with respect to the printing cylinder of the above-identified Rueger pat ent, which cylinder is shown in phantom and identified on the drawing as 32 FIG. 3, US. Patent 2,820,956.

Herein it will be seen that the magnetic ink 10 in the form of finely divided particles of a suitable material is contained in a hopper 1 1 which may be agitated or vibrated if necessary to assist the free flow of the ink downward under the influence of gravity for pickup by the conveyer 20 and presentation to the printing cylinder (32.)

The quantity of ink that is delivered from the hopper 1-1 is a function not only of the physical dimensions of the hopper but also of its spacing from the conveyer 20, and the speed of the conveyer itself. The conveyer 20 is magnetized in a manner hereinafter to be described and by virtue of its rotation beneath the hopper 11 will attract the lowermost ink particles in the mass causing them to adhere to the conveyer, the adjacent particles above these lowermost ones being inhibited from building up on the conveyer by the edge 11a of the hopper. The coaction of the hopper and the rotating conveyer 20 thus acts somewhat in the fashion of a picker-feed which slices the lowermost stratum of magnetic particles from the comminuted mass and deposits it evenly over the surface of the conveyer, or also similar to the action of reservoir and doctor blade in conventional ink applicators. By suitable selection of the conveyer speed, the size of the throat opening between the edge of the hopper and the conveyer surface, and strength of the magnetic field, the quantity of ink presented to the printing drum 32 can be accurately controlled. Although it is a desideratum that the peripheral speed of the conveyer 20 be equal to that of the printing drum 32, it is not necessaryto the proper functioning of the apparatus that such be maintained, inasmuch as the conveyer and the printing occupy a spaced relationship. Because of this disposition of the transfer apparatus the difference in the peripheral speed will cause no deleterious action because rolling contact between the printing drum and the conveyer is not necessarily maintained, and in fact a slight difference in the speed of the conveyer and the drum can headvantageously employed to assist the development of the magnetic character image. I

The conveyor 20 is cylindrical in configuration and is formed with a plurality of elemental segments of a mag netic material cast in a non-magnetic plastic of suitable chemical and physical properties. Surrounding the drum is a thin flexible sleeve of synthetic rubber or other suit able elastic material. Provision is made for flexing the sleeve away from the surface of the drum in the area of ad jacency to the print drum so as to deliver the ink which is magnetically attracted to the conveyor to the magnetic character image on the print drum. This flexing is effected by means of an air blast and forms in the elastic sleeve a. bubble or ridge which moves the ink onto the print Specifically, and with reference to FIGS. 2 and 3 the conveyor 20 consists of a hollow shaft 20a integral'with a radial flange 20b, which flange and shaft are constructed of brass or other suitable non-magnetic material. A series of slots formed around the circumference of the flange 20b support the magnetic segments 22 and 23 to form a shell similar in configuration to the bars of a commutator of a conventional D.C. electric motorconstruction. The segments 22 and 23 are evenly spaced about the circumference-of the flange 20b and are so disposed therein that they all lie in a common cylindrical surface. To further bind the segments in a unit construction and to present a smooth surface the segments are encased in a plastic mass 24, which mass is cylindrical in its outer and inner surfaces. The plastic is formed with a plurality of radially extending apertures 24a, which apertures are located in the interspace between the segments 22 and 23 and extend entirely through the plastic mass so as to provide air ports from the inner to the outer surface of the conveyor. The segments 22 are formed with integral radially extending tabs 22a, which tabs are flush with the inner cylindrical surface of the plastic.v The segments 23 are similarly formed but the tabs 23a are spaced from the tabs 22a. The segments 22 and 23 are arrayed in alternate succession around the circumference of the flange 20b so that all of the tabs 22a are aligned in a common plane and the tabs 23a are aligned in a second common plane parallel to the first plane and spaced from it along the axis of the cylinder, both planes being perpendicular thereto. Thus, by this disposition, coaction between the north and south poles of an electromagnet hereafter to be described will magnetize the segments 22 and 23 in alternate north and south polarity. The elastic sleeve hereinabove referred to is shown in FIGURES 2 and 3 and identified by the reference character 21. As will be apparent, it adheres to the cylinder by virtue of its own elasticity but not so tightly that itcant be flexed away from the drum by the air blast means hereinafter to be described.

The conveyor 20 is suitably journaled for rotation in bearings as for instance, the ball bearings 25, and is driven in rotation by any suitable means such as pulley 26 and belt27.

Internally disposed within the hollow shaft 20a is a stationary magnet support and air blast tube 30a, which tube at one end is connected to a source of air pressure by suitable flexible hose 35 and at the other end extends into the interior of the cylindrical conveyor where it terminates in an elongated tuyere, which extends radially to the left as viewed in FIG. 1 so as to blow air through the holes 24a so as to flex the band 21 against the print drum 32. The tuyere 30b is formed much in the configuration of a vacuum cleaner nozzle so as to present to the apertures 24a a long slotted opening, which is parallel to the segments of the cylinder as they rotate past, and which fits closely to the inner surface of the cylinder so as to seal off any undue air escape except through the ports that are directly exposed.

Secured to the end of the air blast tube 30a, internally of the drum 20, is an electromagnet 33, which magnet consists of two axially spaced shoes 33a and 33b, which shoes are so spaced as to coact with the tabs 22a and 23a of the segments 22 and 23. These shoes are formed with a cylindrical outer surface whose radial dimension is slightly less than the inner radius of the drum 20 so as to form an air gap of small dimensions between the shoes and the respective segments. The return magnetic path between the shoes is effected by an integral cylindrical hub which is secured to the blast tube 30a. Coils are wound about the shoes 33a and 33b in such handas to provide a unidirectional magnetic field when the coils (identified as 34) are energized with a direct current. A complete magnetic circuit is thus provided from the shoe 33a, the air gap existing between it and the tab 22a, the gap between adjoining segments 22 and 23, the air gap existing between the. tab 23a and the shoe 33b, the cylindrical hub and back to the shoe 33a. Thus it will be seen that thesegments 22 and-23- are respectively energized with opposite magnetic polarity so,that any particle of the magnetic; ink dePOSe tednn surface btthedrum as itisrotated beneaththe 4 l hopper 11 will tend to be aligned between the thus created north and south poles of the segments. As will be apparent from an examination of FIGURE 1 the electromagnet 33 subtends less than a complete arc of the circle and the magnetic attraction thereof, ceases just short of a point of tangency between the conveyor 20and the print drum 32. Thisorientationof'the magnet 33 with respect to-theprint drum coupled with the, separation of the resilient sleeve 21 from the drum 20- by virtue of the air blast achieves an elfective transfer of the ink 10 to the image on the drum 32. It is contemplated that a permanent magnet could be employed in lieu of the electromagnet 33, however by virtue of the external electrical circuitry connected to the leads 34a, the strength of the magnetic field can be ad-. justed as for instance by the adjustable resistance 41 to regulate the quality of the magnetic printing. Also by use of external circuitry, as for instance the relay 40 and its associated contacts 40a, the magnet energizing current can be further controlled from the printer itself so that magnetic withdrawal of the ink from the hopper 11 can be made selective. Similarly, by a suitable solenoid-operated air valve the air introduced through the blast tube 30a can be controlled from the printer so as to effect a selective delivery of the ink to the magnetic image on the printer drum 32.

While the magnet leads 34a have been shownas being led from the open end of the conveyer cylinder for ease of illustration, in actual practice these leads would be carried through the blast tube 301: and brought externally thereof through a suitable air-tight joint. This then permits the end of the cylinder to be closed to the entrance of any stray magnetic ink particles which could con-. taminate the magnetic path internally of the drum. Wherein the pole pieces cover a complete arc of revolua tion the tuyeres would be included in the pole pieces and be compatible in the materials employed so as not to shunt the magnetic circuit. Encapsulation of the magnet structure and drilling a series of holes would suggest itself as a logical expedient to achieve the necessary air distribution.

It is further contemplated that magnetic poles piece configurations other than that illustrated can be advanta-geously employed. For example pole pieces subtending a complete arc of revolution with an exterior surface defining some surface other than a cylindrical one, is logically suggested. In such instance the air gap between the pole pieces 33a and 33b and the respective segment tabs 22a and 23a could be made to vary in accordance with some predetermined mathematical function so as to achieve a variable field strength between the segments 22 and 23 as they revolve.

Thus it will be seen that as the conveyor rotates in a: counter-clockwise direction as viewed in FIGURE 1- comminuted magnetic ink particles 10 disposed in the hopper 11 will be magnetically attracted to the surface of the flexible sleeve 21 to form a uniform stratose dispersion of the ink thereon so that for further rotation of the drum in a counter-clockwise direction the ink will be conveyed to proximity with the print drum 32, where an air blast will flex the resilient band 21 to form an elongatedbubblc in the surface thereof to transfer the ink to the surface of the drum 32 which has been magnetized in image configuration as described in US. Patent 2,820,926. By virtue of the adjustability of the gap between the-hopper 11 and the surface of the drum 20, the speed of the drum, and the strength of the electromagnet, the quantity of ink delivered to the print drum 32 can be accurately controlled so as to provide a fine gradation of print quality control.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be madethercin without departing from the spiritandscopc of the in: v ntion.

What is claimed is:

1. Apparatus for conveying comminuted magnetic material from a bulk source and delivering it to a transfer position in a uniform stratose dispersion comprising, a hopper having a discharge opening therein and containing said material in a bulk mass, a conveyer comprised of a plurality of segments of magnetic material overlaid with a thin resilient web of non-magnetic material means for magnetizing adjacent ones of said segments with opposite magnetic polarity, means for moving said conveyer through a predetermined path past said discharge opening wherein the magnetized segments attract the comminuted magnetic particles from the bulk mass in a uniform stratose dispersion disposed over the surface of said resilient web to said delivery position, and means at said transfer position for flexing said web away from said segments so as to separate said material from said conveyer.

2. Apparatus for conveying comminuted magnetic material from a bulk source and delivering it to a transfer station in a uniform stratose dispersion comprising, a hopper containing said material in a bulk mass and having an elonagted discharge opening therein, a cylindrical conveyer comprising a plurality of segments of magnetic material disposed as elements of a cylinder overlaid by a resilient sleeve of non-magnetic material, the said conveyer being disposed in close adjacency to said discharge opening so as to define with said hopper an elongated throat for the passage of said material, means internally of said cylindrical conveyer for magnetizing adjacent ones of said segments with opposite magnetic polarity, an elongated tuyere internally disposed within said conveyer opposite said transfer station for directing a blast of air against said sleeve to flex it away from said segments to separate said material, and means for rotating said conveyer at a predetermined velocity past said hopper.

3. A conveyer and applicator for delivering comminuted magnetic ink from a bulk source and applying it at a transfer station in a uniform stratose dispersion to the magnetic surface of a printing device wherein the surface has been fragmentarily magnetized in character data configuration comprising, a hopper containing the said ink in bulk mass and having a discharge opening therein, a conveyer movable from said hopper to said transfer station and comprising a plurality of closely spaced segments in ordered array and constructed of magnetic material overlaid by a flexible web of nonmagnetic material, means coacting with said segments for a predetermined portion of their path of movement for magnetizing adjacent ones thereof with opposite magnetic polarity, and means at said transfer station for flexing said web away from said segments and against said 6 surface of said printing device, whereby the ink in said bulk source is attracted to said conveyer in a thin stratose dispersion, carried to the transfer station and deposited on the magnetized character areas of the printing device to provide uniformly inked data representations for printing purposes.

4. An applicator for applying a controlled quantity of magnetic ink in a uniform stratose dispersion to the moving surface of a magnetic printing device to develop the magnetic latent image thereon as an incident to printing, comprising, a hopper containing a bulk mass of the magnetic ink in comminuted form and having downwardly converging sides defining a discharge opening for the ink, a rotatable cylindrical ink conveyer disposed beneath said discharge opening so as to define together with the sides of said hopper a throat for limiting the quantity of ink to be extracted from the hopper by the conveyer, the said conveyer being further disposed with respect to the moving printing surface of said magnetic printing device so as to lie in close adjacency thereto and comprising a plurality of spaced parallel segments of magnetic material supported in a non-magnetic mass wherein the segments and the mass define a hollow cylinder the segments thereof forming elements of the outer cylindrical surface, and the mass having radially extended apertures disposed between the said segments which segments have radailly inwardly depending tabs the ends of which lie in the inner cylindrical surface of the conveyer the tabs being staggered so as to be disposed in two circular rows in alternate succession, a flexible sleeve surrounding said cylinder, an electromagnet disposed internally of said cylinder and having a pair of arcuate shaped spaced pole pieces aligned to coact with said tabs whereby adjacent ones of said segments are magnetized with opposite magnetic polarity, and an elongated tuyere with a gaseous fluid under pressure and disposed internally of said cylinder to direct the flow of gas through said apertures to flex said sleeve away from said cylinder to separate the ink from the magnetic influence of said segments and to present the ink to the moving printing surface of said printing device for attraction and adherence thereto in conformity with the latent magnetic image thereon.

5. The applicator of claim 4 wherein means are provided for varying the magnetic field strength of said electromagnet.

References Cited in the file of this patent UNITED STATES PATENTS 411,899 Molfatt Oct. 1, 1889 675,162 Noble May 28, 1901 2,786,440 Giaimo Mar. 26, 1957 2,841,461 Gleason July 1, 1958 

